1. Field of the Invention
This invention relates to dosage forms for buccal administration of medicaments and more particularly to buccal dosage forms providing rapid bioavailability of pharmaceutically active compounds administered by the buccal route.
2. Brief Description of the Prior Art
Administration of pharmaceutical compounds through the buccal mucosa has been found to be an effective means of supplying an effective dose directly to the bloodstream of a patient. The buccal route of administration avoids the possibility that the pharmaceutical compound will be destroyed in the gastrointestinal tract before it can be absorbed, and also eliminates the danger of first-pass inactivation in the liver after absorption. Typically, the buccal dosage form is placed in the buccal cavity between the gum and the cheek, where it dissolves in the patient's saliva, releasing the medicament into the buccal cavity in close proximity to the capillary bed of the oral mucosa. The pharmaceutically active compound then enters the blood in the capillary bed by diffusion through the mucosal tissue and is distributed in the bloodstream to the rest of the body. The rate at which the medication is supplied to the body depends upon, among other things, the rate at which the buccal dosage form dissolves in the mouth. In particular, with patients who have a deficient flow of saliva, a condition found with some frequency in elderly patients and in patients who may be taking medication which tends to depress the flow of saliva, the dosage form may dissolve slowly and supply the medication at a rate which is slower than desired. Such patients also have to endure the discomfort of retaining a foreign object in the buccal cavity, often between the cheek and gum, for a longer period than they might wish.
Hence, a need has continued to exist for a buccal dosage form which will rapidly disintegrate or lose its perceptible shape in the mouth and thereby rapidly and comfortably release its medicament into the buccal cavity independently of the rate of flow of the patient's saliva.